Pump with sealed impeller hub



Nv.4,1958 w, DOBLE 2,858,769

PUMP WITH SEALED IMPELLER HUB Filed Aug 22, 1955 rates PUMP WITH SEALED IMPELLER HUB AilVarr'en Doble, North Holiywood, Calif., assignor to Jabsco 'Pump Company, Burbank, Calif., a corporation `of California Application August 22, 1955, Serial No. 529,713

13 Claims. (Cl. 10S-117) The 'present invention relates in .general torotary pumps and,"since it is particularly applicable to rotary pumps having impeliers of rubber, or like materials, it will he considered in such iconnection herein for -purposes of v illustration.

vThis specification 'discloses subject matter 'whichis disclosed and claimedin the copending application of Robert E. Yaugher and'myself, Serial No. 447,163, tiled August 2, 1954, now abandoned, reference to whichis hereby made.

The aforementioned copending application discloses a rubber-impellered pump which includes a pump housing having an impeller chamber, a shaft having a projectn ing end extending inwardly into the impeller chamber, a cup-shaped hub telescoped over and enclosing the projecting end ofthe shaft, anfimpeller bonded onto the hub and Vdisposed in the impeller chamber, an inwardly struck dirnple on the hub disposed in a recess' in the shaft to transmit rotation of the shaft to` the hub, A'and sealing means engaging the pump housing and 'the hub outwardly of 'the impeller chamber for providing a uidtightseal between the pump housing and the hub, the

hub projecting outwardly beyond one end ofthe impeller n into engagement with the shaft to corrode the shaft'and possibly cause the impeller hub to stick thereto so that it is difcult or impossible to remove, particularly -v'vhere the shaft is a steel shaft 'susceptible to rusting.

Because of the foregoing, the impeller and hub are readily replaceable in a minimum 'of time and with 'simple tools, this being an important feature, particularly in marine installations 'where satisfactory pump operation may be a life or death matter.

Even with the foregoing advantages of the construction illustrated in the copending application mentioned, I havefound that some corrosion of the shaft-may take place within the hub, particularly in the corrosive atmospheric environment found yin marine applications of the invention. Such shaft and/ or hub corrosion occasionally makes the impeller difficult to remove from the shaft, particularly in the case of a steel shaft, whichis undesirable for the reasons mentioned.

.Considering how this corrosion of the shaft within the impeller hub may occur, despite the fact that the pumped uid is prevented from coming in contact with 'thevshaft byy the aforementioned sealing means between the hub atent 2,858,259 Patented Nov. 4, 1958 rotate on slightly different axes because of the side load imposed on the impeller by the discharge pressure of the pumped fluid and the iiexing of the vanes as they engage the vane-ilexing cam. Such rotation of the hub and the shaft about slightly spaced axes cannot be prevented without sacrificing the relatively loose mounting of the hub on the shaft, which would be undesirable since it would make the impeller extremely difficult toremove and would make it impossible to remove without special tools and equipment. Since the hub and the' shaft do rotate about slightly diiferent axes, there is always a crescent-shaped space `or clearance between-the shaft and and the pump housing, the impellerv hub and the shaft hub and the shaft occurs.

the hub, and the configuration of this space changes during each revolution because some slippage between the This changing 'configuration of the crescent-shaped space between the hub and shaft results in la pumping action so that air is pumped into and out of such space as the shaft -and impeller hub are rotated. Consequently,` if the Ipump is operated in a corrosive atmosphere, 'such as the damp and salty atmosphere characteristically associated with the ocean, the air pumped or circulated through the clearance between the impeller hub and the shaft tends to corrode both of'these elements, and particularlyl tends to rust the shaft if it is formed of steel. `Sguchcorrosion may result vin extreme difficulty in removing the impeller and its hub from the shaft for replacement purposes, which is obviously undesirable since it 'may place humanlife in jeopardy.

In'view ofall of the foregoing, a primary object of the invention `is` to provide a pump -having sealing means for providingv aHfiuid-tight seal between the hub of the impeller and the shaft so that no circulation of the atmosphere in which the pump is operated can take place through the clearance between `the impeller hub and the shaft. 4This factor, coupled with isolating the shaft Vfrom the l'pumped fluid in the mannerhereinbefore -outlined, results' in a structure wherein ithe shaft is substantially completely freed of corrosive'ir'iiluences. Consequently, the imp'ellerand its hub mayjalways be removed readily with substantially no possibility 'of sticking tothe shaft, which is an important feature of the invention.

y Another object is to provide a sealing means between the hub and lthe shaft which includes a sleeve encircling the shaft and engaging the outer end of the hub, beyond the sealing means between the hub and the pump housing. A related object is to provide the 'hub with a convergent outer end engaged by the sealing sleeve to insurea fluidtighltseal.

Still another. object is to 'provide resilient means encircling the sealing sleeve mentioned for biasing the sealing sleeve into Huid-tight engagement with both the convergent` outer end of the huband-the shaft,

Another object is to provide aV bearing for the shaft which is also engaged -by Vthe `sealing sleeve, whereby lthe sealing sleeve performs the dual function of excluding' air from the clearance `between the hub and the shaft and from the bearing.

The vforegoing objects, advantages, features and results of the 'present invention, together with various other objects, advantages, features and results thereof which view portion of Fig. 1 but illustrating another embodiment of` a pump of the invention.

Referring particularly to Figs. 1 and 2 of the drawing, the numeral designates a pumpl housing which provides an impller chamber 12 for an impeller 14 of rubber, or like material. The impeller 14 inclu-des vanes 16 adapted to be flexed by a cam 18 to produce the characteristic pumping action of pumps of this nature as the impeller is rotated.

Aligned with the pump housing 10 is a housing 20 for a bearing 22, the bearing housing being shown as connected to the pump housing 10 in the particular construction illustrated and as being provided with a mounting ange 24 for mounting the pump.

The bearing 22 rotatably supports a shaft 26 having a projecting end 28 which extends into the impeller chamber 12 an-d is encircled by the impeller 14. Telescoped over the projecting end 28 of the shaft 26 is a deep, cup-shaped, sheet metal hub 30 of the impeller 14 which encloses the projecting end 28 of the shaft 26. The impeller 14 is bonded to the hub 30 and the latter is provided with an inwardly struck dimple or detent 32 disposed in a recess 34 in the shaft 26. This recess may either be a keyway, or a chordal recess providing a fiat engageable by the detent 32. Thus, torque is transmitted from the shaft 26 to the impeller 14 by the torque-transmitting connection between the shaft and the hub 30 provided by the detent 32 in the recess 34, and by virtue of the fact that the impeller is bonded to the hub.

The pump of the invention includes sealing means 36 engaging the pump housing 10 and an axially projecting sleeve portion of the hub 30 outwardly of the impeller chamber 12 to prevent leakage from the impeller chamber, it being noted that the pump housing 10 opens to the atmosphere outwardly of the sealing means 36 so that any leakage which does occur may escape. With this construction, it will be apparent that none of the,

pumped uid can come in contact with the shaft 26, being prevented from so doing by virtue of the fact that the hub 30 projects beyond the impeller 14 and is sealed relative to the pump housing 10 by the sealing means 36. Also, since the sealing means 36 engages the hub 30, and not the shaft 26, the `sealing means 36 cannot produce wear of the shaft.

In order to prevent circulation of air from the surrounding atmosphere through the clearance between the hub 30 and the projecting end of the shaft 26, which clearance is necessary to provide ready installation and removal of the impeller 14 and its hub 30, I provide a sealing means 40 for producing a fluid-tight seal between the axially projecting sleeve portion of the hub 30 and the shaft. As best shown in Fig. 2 of the drawings, the sealing means 40 includes an elastomeric sealing sleeve 42 which encircles the shaft and which engages a convergent outer end 44 of the hub 30.v The sealing sleeve 42 may be provided with internal annular ribs 46 to promote duid-tight engagement with the shaft 26, and a garter spring 48 may encircle the sealing sleeve to bias it inwardly into sealing engagement with the convergent end 44 of the hub and with the shaftbut these additions or refinements are not necessary to the invention.

In the embodiment illustrated in Figs. 1 and 2 of the drawings, one end of the sleeve 42 also engages the bearing 22 to prevent leakage of air, or other fluids, into the interior of the bearing. In this connection, it should be noted that the convergent end 44 of the hub 30 tends to cause the sealing sleeve 42 to shift axially along the shaft 26 into positive sealing engagement with the bearing, Vdue to the elastic nature of the sealing sleeve. By using a garter spring surrounding the sealing sleeve, this effect can be augmented.

An annular sealing element, such as an O-ring 50, encircles the exterior of the bearing 22 and provides a uid-tight seal between it and the bearing housing 20,

Vthereby preventing leakage of oil or vapor from the engine to which the pump is attached, as by the iange 24.

Referring to Fig. 3 of the drawing, the embodiment illustrated therein is similar to the one just described and corresponding reference numerals are employed insofar as possible. In the embodiment of Fig. 3, the elastic sealing sleeve 42 seals only the clearance between the hub 30 and the shaft 26, and does not seal the bearing 22. Thus, in this embodiment, the sealing sleeve 42 is 'simply seated against a washer 52 abutting a shoulder 54 on the shaft. The function of the sealing sleeve 42 in sealing the bearing 22 in the previous embodiment, and the function of the O-ring 50 of the previous embodiment, are performed by a sealing means 56 in the embodiment of Fig. 3, this sealing means engaging the bearing housing 20 and the shaft 26 as shown.

Thus, the present invention provides a construction wherein the shaft Within the impeller hub is completely isolated to reduce corrosion to ya minimum, thereby insuring easy installation and removal of the impeller at all times, which is an important feature.

Although I have disclosed exemplary embodiments of my invention herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims allowed to me and appearing hereinafter.

I claim as my invention:

l. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft extending into said impeller chamber; an impeller in said impeller charnber and including an impeller hub encircling said shaft, said impeller being xed on said hub, said impeller hub loosely fitting said shaft so as to be readily removable therefrom; means for transmitting rotation of said shaft to said impeller hub; a sleeve portion fixed on said impeller hub and projecting from one end of said impeller along and encircling said shaft; and means engaging and providing a fluid-tight'seal between said sleeve portion and said shaft.

2. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft extending into said impeller chamber; an impeller in said'impeller chamber and including an impeller hub encircling said shaft, said impeller being fixed on said hub, said impeller hub loosely fitting said shaft so as to be readily removable therefrom; means for transmitting rotation of said shaft to said impeller hub; a sleeve portion fixed on said impeller hub and projecting from one end of said impeller along and encircling said shaft; means engaging and providing a fluid-tight seal between said sleeve portion and said shaft; and means engaging and providing a fluidtight seal between said sleeve portion and said pump housing.

3. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft extending into said impeller chamber; an impeller hub in said impeller chamber and encircling said shaft, said impeller hub loosely fitting said shaft so as to be readily removable therefrom; a rubber impeller in said impeller chamber and bonded to said hub; means for transmitting rotation of said shaft to said impeller hub; and means engaging and providing a fluid-tight seal between said impeller hub and said shaft.

4. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft extending into said impeller chamber; an impeller hub in said impeller chamber and encircling said shaft, said impeller hub loosely fitting said shaft so as to be readily removable therefrom; a rubber impeller in said impeller chamber and bonded to said hub; means for transmitting rotation of said shaft to said impeller hub; means engaging and providing a duid-tight seal between said impeller hub and said shaft; and means engaging and providing a uid-tight Sl. between said impeller hub and said pump housing.

5. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft having a projecting end extending inwardly into said impeller chamber; an impeller in said impeller chamber and encircling said projecting end of said shaft, said impeller including a central hub which is closed at its inner end to venclose said projecting end of said shaft and which extends outwardly along said shaft out of said impeller chamber so that the outer end of said hub is located outwardly of said impeller chamber, said impeller being fixed on said hub, said hub loosely fitting said shaft so as to bey readily removable therefrom; means for transmitting rotation of said shaft to said hub; and means engaging and providing a fluid-tight seal between said hub and said shaft.

6. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft having a projecting end extending inwardly into said impeller chamber; an impeller in said impeller chamber and encircling said projecting end of said shaft, said impeller including a central hub which is provided with a closed inner end to enclose said projecting end of said shaft and which extends outwardly along said shaft out of said impeller chamber so that the outer end of said hub is located outwardly of said impeller chamber, said impeller being fixed on said hub, said hub loosely fitting said shaft so as to be readily removable therefrom; means for transmitting rotation of said shaft to said hub; and sealing means engaging said outer end of said hub and said shaft for providing a fluid-tight seal between said hub and said shaft.

7. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft having a projecting end extending inwardly into said impeller chamber; an impeller in said impeller chamber and encircling said 'projecting end of said shaft, said impeller including a central hub which is provided with a closed inner end to enclose said projecting end of said shaft and which extends outwardly along said shaft out of said impeller chamber so that the outer end of said hub is located outwardly of said impeller chamber, said impeller being fixed on said hub, said hub loosely fitting said shaft so as to be readily removable ltherefrom; means for transmitting rotation of said shaft to said hub; sealing means engaging said outer end of said hub and said shaft for providing a fluid-tight seal between said hub and said shaft; and sealing means engaging said pump housing and engaging said hub inwardly of said outer end thereof for providing a fluid-tight seal between said hub and said pump housing.

8. A pump as dened in claim 6 wherein said hub is a deep, one-piece, sheet metal cup, said rotation-transmitting means including an inwardly-struck detent on said cup disposed in a recess insaid projecting end of said shaft. j

9. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft having a projecting end extending inwardly into said impeller chamber;

an impeller in said impeller chamber and encircling said projecting end of said shaft, said impeller including a central hub which is provided with a closed inner end to enclose said projecting end of said shaft and which extends outwardly along said shaft out of said impeller chamber so that the outer end of said hub is located outwardly of said' impeller chamber, said impeller being fixed on said hub, said hub loosely fitting said shaft so as to be readily removable therefrom; means for transmitting rotation of said shaft to said hub; and sealing means engaging said outer end of said hub and said shaft for providing a fluid-tight seal between said hub and said shaft, including a sealing sleeve encircling said shaft and engaging said outer end of said hub, said outer end of said hub being convergent.

10. In a pump, the combination of: a pump housing providing an impeller chamber; a shaft having a projecting end extending inwardly into said impeller chamber; an impeller in said impeller chamber and encircling said projecting end of said shaft, said impeller including a central hub which is provided with a closed inner end to enclose said projecting end of said shaft and which extends outwardly along said shaft out of said impeller chamber so that the outer end of said hub is located outwardly of said impeller chamber, said impeller being fixed on said hub, said hub loosely fitting said shaft so as to be readily removable therefrom; means for transmitting rotation of said shaft to said hub; sealing means engaging said outer end of said hub and said shaft for providing a fluid-tight seal between said hub and said shaft, including a sealing sleeve encircling said shaft and engaging said outer end of said hub, said outer end of said hub being convergent; and sealing means engaging said pump housingv and engaging said hub inwardly of said lconverging outer end thereof for providing a fluidtight seal between said hub and said pump housing.

l1. A pump as defined in claim 10 including a bearing carrying said shaft and located outwardly of said convergent outer end of said hub.

12. A pump as defined in claim 1l wherein said sealing sleeve engages said bearing to seal same.

13. A pump as defined in claim 9 including resilient means for biasing said sealing sleeve into engagement with said convergent outer end of said hub and said shaft.

References Cited in the file of this patent UNITED ysTArEs 'PATENTS 1,978,689 Peters Oct. 30, 1934 2,180,401 Cornell Nov. 21, 1939 2,189,356 Briggs Feb. 6, 1940 2,243,227 Stratton May 27, 1941 2,245,866 McLachlan June 17, 1941 2,635,553 Gordinier Apr. 21, 1953 2,671,408 Kreitchman. V Mar. 9, 1954 2,711,136 Arnold June 21, 1955 2,782,723 Doble et al. Feb. 26, 1957 2,789,511 Doble Apr. 23, 1957 

